Pawl and ratchet device



UNlTED STATES fATENT OFFICE.

MARTIN NYSTROM, or cnroneo, ILLINOIS, Assmnon To runBnUNswIoK-nALKnoonnnnnnn COMIPANY, or cnrcneo, ILLINOIS, n oonronn'rronor DELAWARE.

PA'WL AND RATCHET DEVICE.

Specification of Letters Patent.

Patented Feb. 14, 1922.

Original application filed. August 16, 1919, Serial No. 317,885. Dividedand this application filed March 22, 1920. Serial No. 367,740.

T 0 all whom it may concern Be it known that I, MARTIN Nrs'rnon, acitizen of the United States, residing at Chicago, in the county ofCool: and State of Illinois, have invented certain new and usefulImprovements in Pawl and Ratchet Dcvices, of which the following is aspecification.

This application is a division of my application, Serial No. 317,885,filed August 16, 1919, upon which Patent No. 1,861,176 was grantedDecember 7 1920.

The object of this invention is to provide a pawl and ratchet mechanismwhich Wlll operate noisclessly and which is, therefore,

especially adapted for locking the winding shaft of a phonograph springmotor.

The invention also has for its object to provide a pawl and ratchetdevice comprising but few parts which can be easily manufactured andassembled at comparatively low cost, which possess high efficiency inuse as a locking device and which may last 1ndefinitely without gettingout of order. In the accompanying drawings illustrating a selectedembodiment of the invention- Fig. 1 is a sectional view showing theinvention applied to the winding shaft of a phonograph motor, a part ofwhich is shown.

Fig. 2 is a side elevation, partly broken away, of the pawl and ratchet.

Fig. 3 is a top plan view.

Referring to the drawings, 4: is a winding shaft mounted in the frame 5of a phonograph motor and isprovided with worms 6 which mesh with wormgears 7 for winding the springs on the shafts 8. The usual winding crankis applied to the end 4- of the winding shaft.

The toothed locking pawl 9 is pivoted at 9 to the motor frame 5 and itis arranged to engage the teeth of the ratchet wheel 10 to lock thewinding shaft against reverse movement. Spring fingers 11, 12 are piv;otally connected by a pin 13 to the free end of the pawl and projectlaterally in parallel relation on opposite sides of the ratchetwheel andyieldingly engage the same. These spring fingers preferably constituteparts of a clamping member 14: which is secured by the pin 13 on thepawl and consists of a metal strip bent upon itself to embrace the pawland ratchet and cut away to accommodate the winding shaft and facilitateassembly of the parts. The fingers are provided with indentations 11',12 to insure frictional engagement with the ratchet wheel, and one ofthe fingers, as 12, is provided with a projection 15 to engage the stop16 on the motor frame.

From the foregoing description it will be noted that the spring fingerclamping member 14. is suspended by the pin 13 from'the free end of thepawl and the teeth of the pawl are normally engaged with the teeth ofthe ratchet wheel. Then the winding shaft is turned in the direction ofthe arrow (Fig? 2) to wind the springs, the ratchet will revolve withthe shaft and, by reason of the frictional engagement of the springfingers with the ratchet wheel, the clamping member will be carried tothe right and thereby disengage the pawl from the ratchet wheel. Themovement of the clamping member and the pawl is limited by the stop 16on the motor frame and therefore when the projection 15 on the clampingmember engages this stop, the ratchet wheel will continue to turn freelybetween the spring fingers of the clamping frame and be free fromengagement with the pawl throughout the winding operation. When thesprings have been wound sufiiciently or at any time the windingoperation is stopped, a slight reverse movement of the winding shaftratchet wheel will carry the clamping member to the left (Fig. 2) byreason of the frictional engagement of the fingers with the sides of thewheel until the pawl is again engaged with the ratchet wheel. It willthus be noted that throughout the winding operation the pawl is freefrom engagement with the ratchet wheel and hence the noise common toratchet devices occasioned by the pawl riding over the ratchet teethduring the winding operation is entirely eliminated.

I have illustrated the invention embodied in a phonograph motor becauseI have used it in this way and have found that it operates eflicientlyand noiselessly in the manner set forth and for the desired purpose. Theinvention consists of very few parts which can be easily made andassembled and which are not liable to get out of order or to wearmaterially in actual use. The invention may he used for other purposesthan to look a spring winding shaft of a phonograph motor, and I do notdesire or intend to limit the invention to this particular embodiment.

I am aware that changes in the form and proportion and details of theconstruction may be made to adapt the invention for differentembodiments and for different associations without departing from thespirit of the invention, and I reserve the right to make all changeswhich fairly fall within the scope of the following claims.

I claim:

1. The combination of a rotary shaft, a ratchet wheel rigid on saidshaft, a pawl engaging said'ratchet wheel to lock the shaft againstreverse movement, and spring fingers pivotally connected to the pawlandfrictionally engaging the sides of the ratchet wheel to be operated bythe ratchet wheel. to shift the pawl out of engagement with the ratchetwheel on the forward movement of the shaft and ratchet wheel and toreturn the pawl into operative engagement with the ratchet wheel uponreverse movement of the shaft and ratchet wheel.

2. The combination of a rotary shaft, a ratchet wheel rigid on saidshaft, a pawl engaging said ratchet wheel to lock the shaft againstreverse movement spring fin gers pivotally connected to the free end ofthe pawl and frictionally engaging the sides of the ratchet wheel to beoperated to shift the pawl out of contact with the ratchet wheel on theforward movement of the shaft and ratchet wheel and to return the pawlinto operative engagement with the ratchet wheel upon reverse movementof the shaft and ratchet wheel, and a stop for limiting the movement ofthe pawl.

3. The combination of a rotary shaft, a ratchet wheel rigid on said.shaft, a pawl 4 engaging said ratchet wheel to lock the shaft againstreverse movement, and a clan1ping device pivotally connected to the freeend of the pawl and comprising spring fingers frietionally engaging thesides of the 4 ratchet wheel to be operated by the ratchet wheel toshift the pawl out of engagement with the ratchet wheel on the forwardmovement of the shaft and ratchet wheel andto return the pawl intooperative engagement 5 with the ratchet wheel upon reverse movement ofthe shaft and ratchet wheel.

4-. The combination of a rotary shaft, a ratchet wheel rigid on saidshaft, a pivoted pawl engaging said ratchet wheel to prevent reversemovement of the shaft and ratchet wheel, and a clamping member carriedby the free end of the pawl and frictionally engaging the sides of saidwheel to be operated to shift the pawl out of en- 6 gagement with theratchet wheel on the forward movement of the shaft and ratchet wheel andto return the pawl into operative engagement with the ratchet wheel uponreverse movement of the shaft and ratchet wheel, a projection on saidclamp ing member, and a fixed stop to beengaged by said projection tolimit the dis engaging movement of said pawl and clamping member.

MARTIN NYSTROM.

